664967851 has 2 divisors, whose sum is σ = 664967852. Its totient is φ = 664967850.

The previous prime is 664967783. The next prime is 664967857. The reversal of 664967851 is 158769466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664967851 - 2²¹ = 662870699 is a prime.

It is not a weakly prime, because it can be changed into another prime (664967857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332483925 + 332483926.

It is an arithmetic number, because the mean of its divisors is an integer number (332483926).

Almost surely, 2^664967851 is an apocalyptic number.

664967851 is a deficient number, since it is larger than the sum of its proper divisors (1).

664967851 is an equidigital number, since it uses as much as digits as its factorization.

664967851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2177280, while the sum is 52.

The square root of 664967851 is about 25786.9705665478. The cubic root of 664967851 is about 872.8378074699.

It can be divided in two parts, 66496 and 7851, that added together give a palindrome (74347).

The spelling of 664967851 in words is "six hundred sixty-four million, nine hundred sixty-seven thousand, eight hundred fifty-one".